Reward and number of choices in children's probability learning: An attempt to reconcile conflicting findings

Five event schedules (75:0, 75:25, 75:0:0, 72:25:0, 75:12.5:12.5) were examined in a size discrimination task with penny rewards and plastic token markers. The subjects were 100 fourth graders (mean age = 9.4 years) and 100 undergraduates of both sexes. Whether or not the event probabilities summed to unity proved to be a more important determiner of terminal performance than the number of response alternatives in the task (p < .01). Females maximized more than males (p < .001) and college students more than fourth graders (p < .001). Greater maximization was exhibited by fourth graders in the reward condition (p < .01). These reward effects appeared to be more consistent with a detrimental-effects-of-reward interpretation than either utility or expectancy interpretations.     

Evaluation of infant vocal conditioning.

The use of the operant conditioning paradigm, as it has been applied to infant social, vocal behavior, reflects a failure to take into account the social nature of human infants over and above the rigid theoretical rationale of the paradigm. It is argued that: (1) the baseline procedure used in operant conditioning studies is methodologically and conceptually invalid; (2) the reinforcing stimulus used in social conditioning studies elicits the very response that it is assigned to reinforce; and (3) the effect of the response-reinforcer relationship is not the reinforcement (strengthening) of vocal response rate.     

Imaging,empathy, and causal attribution

Three studies were conducted to test whether imagery accounts for the effects of empathy on attributions, that is, whether attributers construct and scan a mental image of social scenarios the same way that actual participants scan a real environment. According to this interpretation, attributers “see” the world as the participant does and make vicarious attributions. An alternative interpretation holds that subjects base vicarious attributions on recreating the motivations and affect of the actor, so that imaging is irrelevant to empathy and attributions. In the first study, subjects who imagined a story from the perspective of a particular character later showed differential recall of story details as a function of role, but not differential attributions. In Experiment 2, role-taking subjects showed clear effects of imaged perspective on recall for story details, but no effects on attributions of causality for an accident. Further, recall and attribution were uncorrelated. In the last study, empathy and imagery role-taking instructions produced independent effects: imagers showed pronounced perspective-relevant recall and empathizers did not. Neither showed unambiguous vicarious attributions. Recall and attribution were again uncorrelated. These studies suggest that the imagery explanation of empathy effects is untenable, and imply that the recall of perspective-relevant details is unlikely to mediate attributions of causality in imaginary scenarios.     

Retention of conditioned inhibition in a bar-press suppression paradigm

In three experiments, the retention of conditioned inhibition in rats was examined over long intervals. Retention deficits of conditioned inhibition were found at 21 days, although conditioned excitation was relatively stable over time. This loss of conditioned inhibition was demonstrated using both the summation and the retardation of learning techniques in a bar-press suppression paradigm. Furthermore, retention differences were found between within-groups and between-groups generalization tests of conditioned inhibition, using the summation procedure. These differences were interpreted within a retrieval-oriented model of memory.     

Axiomatic and numerical conjoint measurement: An evaluation of diagnostic efficacy

Synthetic data are used to examine how well axiomatic and numerical conjoint measurement methods, individually and comparatively, recover simple polynomial generators in three dimensions. The study illustrates extensions of numerical conjoint measurement (NCM) to identify and model distributive and dual-distributive, in addition to the usual additive, data structures. It was found that while minimum STRESS was the criterion of fit, another statistic, predictive capability, provided a better diagnosis of the known generating model. That NCM methods were able to better identify generating models conflicts with Krantz and Tversky's assertion that, in general, the direct axiom tests provide a more powerful diagnostic test between alternative composition rules than does evaluation of numerical correspondence. For all methods, dual-distributive models are most difficult to recover, while consistent with past studies, the additive model is the most robust of the fitted models.Douglas Emery is now at the Krannert Graduate School of Management, Purdue University, West Lafayette, IN, on leave from the University of Calgary.     

A general scheme for the analytic decomposition of objective test scores: Illustrative demonstrations using the Rod-and-Frame test and the Müller-Lyer illusion

Objective tests of personality typically include a number of items or trials; the total score on the test is the sum of the subject's “correct” responses across all such trials. Normally, the trials are varied systematically across various facets of the test design, so that the total score represents a composite measure of accuracy averaged across these test facets. However, since only one score is computed for each subject, some potentially important kinds of individual differences—namely all those associated with each particular variation in the test design—are treated solely as measurement unreliability. Such a psychometric stance may serve to obscure more differentiated types of individual differences, with the result that composite scores from trials based on one type of experimental design may not be highly related to such scores from trials using a somewhat different design. The present paper presents a general procedure for scoring objective tests more analytically. To illustrate this general rationale, and to demonstrate its potential utility, data have been reanalyzed from two previous studies, one using the Rod-and-Frame test, the other the Müller-Lyer illusion. In both cases, the traditional global accuracy score did not correlate significantly with other theoretically related variables, while a number of component scores were quite highly related.